1. What is... the number of carbon atoms in 12 grams of carbon? the number of oxygen atoms in 16 grams of oxygen? the number of H 2 O molecules in 18grams of water?

2. The Mole

3. Avogadro’s number 1 mole = 6.02 x 10 23 particles 1 mole = 6.02 x 10 23 particles

4. How big is a Avogadro’s number? If we stack 6.02 x 10 23 pennies on top of one another, the stack of pennies could reach the sun and back almost 500 million times! If we stack 6.02 x 10 23 pennies on top of one another, the stack of pennies could reach the sun and back almost 500 million times! A.N. of marbles spread over the surface of the earth would produce a layer of marbles about 50 miles thick. A.N. of marbles spread over the surface of the earth would produce a layer of marbles about 50 miles thick. If the world’s entire population of 6.5 billion people, counting at the rate of one per second, collectively counted to AN, it would take 3 million years. If the world’s entire population of 6.5 billion people, counting at the rate of one per second, collectively counted to AN, it would take 3 million years.

5. One mole of any atom is the atomic mass of that atom, expressed in grams. 1 mole Fe = 55.847 grams 1 mole Fe = 55.847 grams 1 mole H 2 = 2.016 grams 1 mole H 2 = 2.016 grams 1 mole CO 2 = 12 + 16 + 16 = 44 grams 1 mole CO 2 = 12 + 16 + 16 = 44 grams Called “molar mass” Called “molar mass”

6. These equivalences can be used as conversion factors What is the mass in grams of 3.50 moles of copper atoms? What is the mass in grams of 3.50 moles of copper atoms? 3.50 moles x 63.546g = 222 g Cu 1 mole 1 mole How many moles are in 6.195 g of phosphorus? How many moles are in 6.195 g of phosphorus? 6.195g x 1 mole = 0.2000 mole 30.97 g 30.97 g

7. How many grams are in 2.2mol of NaCl? 2.2mol x 58.5g = 128.7g 1 mol 1 mol How many moles are in 5.78g of NaCl? 5.78g x 1 mol =.0988mol 58.5g 58.5g

8. How many moles is 1.20 x 10 23 atoms of Zn? (1.20 x 10 23 atoms) x =.199 moles What is the mass (in grams) of 1.20 x 10 23 atoms of zinc?.199 moles x = 13.0 g

9. How many atoms are in 0.750 grams Zn? 0.750 g x x = 6.90 x 10 21 atoms